Vehicular traffic control often combines visual traffic signals with visual and sometimes auditory or haptic pedestrian signals to indicate to pedestrians a safe time to cross a roadway. Moreover, improvements in vehicle safety have included the introduction of automatic emergency braking systems, automatic steering systems, rearview and surround view cameras, and collision-alert technology. Despite these implementations, pedestrian injuries and fatalities continue to increase, especially in recent years, and represent a large cost to society. Indeed, pedestrian fatalities increased 27% from 2007 to 2016 in the United States. Clearly, there exists a need to improve pedestrian safety.
Most pedestrian fatalities occur during dusk and evening hours, when lighting conditions are poor. According to the Governors Highway Safety Association, 75% of pedestrian fatalities occur during nighttime hours and 2% during dusk. Many deaths occur as a result of the driver not noticing the pedestrian and therefore, having insufficient time to stop to avoid striking the pedestrian. Per a federal crash data study, a pedestrian's likelihood of survival approximates 90% if struck by a vehicle traveling at 20 miles per hour but is diminished to 20% if the vehicle is moving at 40 miles per hour. As a result, there exists a need to improve visibility of pedestrians crossing roadways during naturally low-light conditions.
Thus far, many proposed solutions to the problem of pedestrian visibility have related to providing ground-level, and even in-ground, crosswalk lighting. For instance, U.S. Pat. No. 6,384,742 discloses a plurality of surface-mounted lights that, when activated by a manual switch or sensor, flash along the ground surrounding a pedestrian crosswalk to warn drivers that a pedestrian may have entered the crosswalk and that caution should be exercised. Similarly, Korean patent application 20130083285 discloses a crosswalk safety system including pedestrian guidance indicators as in-ground LED light strips. The light strips provide a visual indicator that pedestrians may safely cross the intersection.
Other proposed solutions relate to above-ground crosswalk lighting. For instance, Korean patent 10127551 teaches a lighting apparatus for pedestrian crossing zone which radiates across a crosswalk to increase visibility of pedestrians. However, this reference does not provide a light frame that may be fixed to an existing traffic signal. Also, this patent does not provide for coordinating the illumination of the device with natural lighting or weather conditions. U.S Pub. Nos. 2017/0038018, 2017/0030538, and 2016/0123547 related to bollard type lighting fixtures that automatically illuminate a pedestrian crosswalk when vehicles and pedestrians are detected. These do not, however, disclose retrofittable use with existing traffic signals but rather operate as a function of the presence of vehicles and pedestrians. Additionally, these lighting figures are not activatable in low-visibility daytime conditions.